✨ feat: add vibration feedback support for UI events

- Add genericVibration class with 5-second cooldown and 1-second pulse
- Integrate vibration triggers for new messages and contact discoveries
- Add conditional compilation support with PIN_VIBRATION guard
- Implement abstract interface for vibration in UITask system

src/helpers/ui/vibration.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#ifdef PIN_VIBRATION
+
+#include <Arduino.h>
+
+/*
+ * Vibration motor control class
+ *
+ * Provides vibration feedback for events like new messages and new contacts
+ * Features:
+ * - 1-second vibration pulse
+ * - 5-second nag timeout (cooldown between vibrations)
+ * - Non-blocking operation
+ */
+
+#ifndef VIBRATION_TIMEOUT
+#define VIBRATION_TIMEOUT 5000  // 5 seconds default
+#endif
+
+class genericVibration
+{
+  public:
+    void begin();       // set up vibration pin
+    void trigger();     // trigger vibration if cooldown has passed
+    void loop();        // non-blocking timer handling
+    bool isVibrating(); // returns true if currently vibrating
+    void stop();        // stop vibration immediately
+
+  private:
+    unsigned long duration;
+};
+
+#endif // ifdef PIN_VIBRATION